Olds/Pontiac 9.3 in an A-Body?

The one I am looking at has a 5x5 bolt pattern. I did look at fabcraft metal works in my search to see if parts were available. Guy is asking $150 for it. Says he is not sure about the gear ratio but thinks it is 2.75:1 and open so both things would have to change. Car currently has a 7.25 SureGrip with 2.94 gear ratio in it and I think it would hold up ok behind the 360 magnum/904 combo I am dropping in so long as I don't drive like I did when I was 19. The problem is I WANT to drive like I did when I was 19. =).